Tab for opening can lid

ABSTRACT

In a case where an indication is provided between a fixed part and a pulling-up part of a tab, the tab is provided with necessary rigidity and disturbance of the indication is suppressed. A tab for opening a can lid includes a pulling-up part provided on one end side in a longitudinal direction of the tab, a pressing-down part provided on another end side in the longitudinal direction, a fixed part provided between the pulling-up part and the pressing-down part and formed by being demarcated by a U-shaped slot and fixed to a can lid body, and a curl part formed continuously at a peripheral edge excluding a connected-piece-cutting trace provided at the pressing-down part, a surface between the fixed part and the pulling-up part is a display surface, and a back surface side of the display surface is an abutted surface against which a shaping tool is abutted.

TECHNICAL FIELD

The present invention relates to a tab for opening a can lid.

BACKGROUND ART

A can lid having an opening tab of stay-on type is commonly known. Sucha can lid has a tab fixed to a panel of a can lid body, and the tabincludes: a fixed part fixed to the can lid body by a rivet; apulling-up part separated from the fixed part due to a slit and pulledup by a finger; and a pressing-down part pressed down in accordance withpulling up of the pulling-up part, with the fixed part serving as afulcrum, and moreover the can lid opens as a score formed at the panelis ruptured by the pressing-down part of the tab so that an openingpiece demarcated by the score sinks into the can.

In such a tab for opening a can lid, force that is exerted on a fingerduring opening operation is reduced by making use of principle ofleverage, according to which the fixed part serves as a fulcrum, thepulling-up part serves as a point of lever, and the pressing-down partserves as a point of action. The length from the fixed part to thepulling-up part is greater than the length from the fixed part to thepressing-down part. Moreover, a curl part is formed for increasingrigidity at a peripheral edge of the tab, which connects the pulling-uppart and the pressing-down part, so that the pressing-down part ispressed down synchronously with pulling up of the pulling-up part.

In general, a hole, which is called a finger hole, is formed between thefixed part and the pulling-up part of the tab. Meanwhile, a tab with nofinger hole between the pulling-up part and the fixed part is also known(see PTL 1). Such a tab may be provided with a tab panel between thefixed part and the pulling-up part, whereby information or a picture isindicated at a part thereof to be able to enhance decorativeness.

CITATION LIST Patent Literature

-   [PTL 1] Japanese Patent Application Publication No. 2017-121967

SUMMARY OF INVENTION Technical Problem

The abovementioned tab is produced from a strip-shaped coil on which aplurality of tabs are continuously arranged. At the time of producingthe same, the tabs are shaped by blanking from the strip-shaped coilthrough multiple steps, in which the coil is, first, subjected tonecessary hole machining, then, the contour shape of each tab is blankedalong an annular cut line excluding a connected-piece, which is to be aso-called carry-point, and, thereafter, necessary tab shape processing,such as irregularity shaping or curl shaping that is implemented toperipheral edges, is performed in a state where the plurality of tabsare continuously arranged on the coil, and eventually theconnected-piece is severed so that the tab is attached to a can lidbody.

In this case, if the connected-piece, which is to be the carry point ispresent both on the left and right sides of the fixed part, the curlpart provided at the peripheral edge is interrupted in the position ofthe connected-piece, and the rigidity of the tab is reduced in theinterrupted position. Therefore, in the abovementioned conventional casewith no finger hole between the fixed part and the pulling-up part, whenthe pulling-up part is pulled up during opening operation, theinterrupted part of the curl part in the position of the connected-piecebecomes a bending point, which causes the tab to be easily bent, wherebythe tab may not have enough rigidity necessary for opening.

The opening tab of stay-on tab-type is a part to which a person holdinga can pays particular attention during opening operation, and the tab isnot severed from a can lid body after opening, hence, by providing to apart of the tab an indication of information or a picture, it ispossible to enhance decorativeness as described above and provideinformation or advertisement effectively.

The indication at the tab may be implemented effectively in a case wherea finger hole between the fixed part and the pulling-up part is removed.However, when indication is implemented between the fixed part and thepulling-up part by, for example, laser marking or ink jet printing and atab panel is shaped to have a downwardly convex surface as in theconventional case, the tool surface of a shaping tool contacts a surfacethat is provided with the indication, and dust generated during lasermarking or ink from ink jet printing is transferred onto the toolsurface, and this may disturb the indication on the tab itself or,during processing on other tabs arranged continuously on thestrip-shaped coil, dust or ink transferred onto the tool surface of theshaping tool may be transferred to the other tabs, which results indisturbing the indication on the other tabs.

Moreover, in tab production, the peripheral edge of the tab is subjectedto curl shaping as described above, and during this processing, a curvemay be created in the fixed part of the tab and the pulling-up part ofthe tab, hence the curve needs to be subjected to reform shaping toflatten the same. At that time, when there is an indication made bylaser marking or ink jet printing between the curved fixed part and thecurved pulling-up part, the dust or ink is transferred to the toolsurface of a shaping tool that performs reform shaping, and this maycause a problem same as described above.

In a case where no finger hole is provided, and the upper surface isformed having a downwardly convex shape, a finger contacts the tab panelwhen pulling up the pulling-up part during opening operation, hencefavorable operational feeling cannot be obtained.

The present invention has been proposed to address such problem. Morespecifically, it is an object of the present invention that, in a casewhere an indication is provided between a fixed part and a pulling-uppart of a tab, the tab is provided with necessary rigidity, indicationdisturbance is reduced, and favorable operational feeling is providedduring opening.

Solution to Problem

In order to solve the problems, a tab for opening a can lid according tothe present invention includes the following configuration.

A tab for opening a can lid, the tab including a pulling-up partprovided on one end side in a longitudinal direction of the tab, apressing-down part provided on another end side in the longitudinaldirection, a fixed part provided between the pulling-up part and thepressing-down part and formed by being demarcated by a U-shaped slot andfixed to a can lid body, and a curl part formed continuously at aperipheral edge excluding a connected-piece-cutting trace at thepressing-down part, wherein a surface between the fixed part and thepulling-up part is a display surface, and a back surface side of thedisplay surface is an abutted surface against which a shaping tool isabutted.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a tab for opening a can lid according to anembodiment of the invention ((a) is a sectional view taken along lineA-A, (b) is a plan view, and (c) is a rear view).

FIG. 2 illustrates a tab for opening a can lid according to anotherembodiment of the invention ((a) is a sectional view taken along lineA-A, (b) is a plan view, and (c) is a rear view).

FIG. 3 illustrates a tab for opening a can lid according to anotherembodiment of the invention ((a) is a sectional view taken along lineA-A, (b) is a plan view, and (c) is a rear view).

FIG. 4 illustrates a tab for opening a can lid according to anotherembodiment of the invention ((a) is a sectional view taken along lineA-A, and (b) is a plan view).

FIG. 5 illustrates a tab for opening a can lid according to anotherembodiment of the invention ((a) is a sectional view taken along lineA-A, and (b) is a plan view).

FIG. 6 illustrate the position of a display part in a tab for opening acan lid according to the embodiment of the invention ((a) corresponds tothe example shown in FIG. 1 and (b) corresponds to the example shown inFIG. 3).

FIG. 7 is a view for illustrating a method for manufacturing a can lidto which a tab for opening the can lid is attached.

FIG. 8 is a view for illustrating a process for forming a tab foropening a can lid ((a) corresponds to a state after a display part isdrawn, (b) corresponds to a state after hole machining, and (c)corresponds to a state after the outer peripheral part is blanked).

FIG. 9 illustrates a process for forming a tab for opening a can lid((a) and (b) correspond to states after irregularity shaping and (c) isa state after curl shaping).

FIG. 10 illustrates irregularity shaping processing to a tab panel ((a)corresponds to a state before shaping and (b) corresponds to a stateafter shaping).

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the drawings. In the following description, the samereference characters among different figures indicate portions havingthe same functions, and their description in connection with thedrawings will not be repeated as appropriate. The direction of the arrowX in FIGS. 1 to 3 indicates the longitudinal direction of the tab foropening a can lid, the direction of the arrow Y indicates the directionorthogonal to the X direction when viewed in a plan view, and the arrowZ indicates the thickness-wise direction of the tab for opening a canlid.

As shown in FIGS. 1 to 3, the tab for opening a can lid (hereinafter asa tab) 1 (1A, 1B, or 1C) has a pulling-up part 2 provided on one endside in the longitudinal direction (in the X direction inillustrations), a pressing-down part 3 on the other end side in thelongitudinal direction (in the X direction in illustrations) and a fixedpart 4 between the pulling-up part 2 and the pressing-down part 3.

A person engaged in opening operation puts a finger on the pulling-uppart 2, and the opening operation is performed by pulling up the part inthe Z direction in illustrations. As the pulling-up part 2 is pulled up,the pressing-down part 3 is pressed down in the opposite direction, andwhen the pressing-down part is pressed down in abutment against thepanel of the can lid body, the score of the can lid is ruptured.

The fixed part 4 is formed by being demarcated by a U-shaped slot 5 andincludes a rivet hole 6 through which a rivet to be provided on thepanel of the can lid body is inserted, and the fixed part 4 is fixed tothe can lid body as the rivet is inserted into the rivet hole 6 andcrimped.

A connected-piece-cutting trace 7 is provided in the center of thepressing-down part 3. Then, a curl part 8 is formed on the outerperipheral edge of the tab 1 excluding the connected-piece-cutting trace7. The curl part 8 increases the flexural rigidity of the tab 1 becausethe tab 1 serves as a lever having the pulling-up part 2 as a point ofeffort, the fixed part 4 as a fulcrum point, and the pressing-down part3 as a point of load. Here, the connected-piece-cutting trace 7 isprovided at the pressing-down part 3, so that the interrupted part ofthe curl part 8 is in a position free from bending force caused when thepulling-up part 2 is pulled up during opening operation, and the tab 1has rigidity necessary for opening the can lid.

The tab 1 (1A, 1B, or 1C) is shaped. In one case, a shaped part 10having a convex shape in the direction opposite to the Z direction isprovided on the periphery of the fixed part 4, and the region betweenthe pulling-up part 2 and the fixed part 4 is shaped. The tab 1 (1A)shown in FIG. 1 is provided with a shaped part 11 in a convex shape(i.e., shaped to have a convex shape on the surface side and a concaveshape on the back surface side) in the Z direction in illustrationsbetween the pulling-up part 2 and the fixed part 4. The tab 1 (1B) shownin FIG. 2 is provided with a shaped part 12 shaped to have a convex domeshape in the Z direction in illustrations between the pulling-up part 2and the fixed part 4. The tab 1 (1C) shown in FIG. 3 has a regionbetween the pulling-up part 2 and the fixed part 4 flattened by reformshaping.

Tab 1 (1A, 1B, or 1C) includes a display surface 20. Although not shown,the display surface 20 is the surface between the pulling-up part 2 andthe fixed part 4 which is formed with a display part for example for atwo-dimensional code, a logo, a picture, letters, and numbers drawn bylaser marking or ink jet printing. The back surface side of the displaysurface 20 is an abutted surface 21 for performing the shapingprocessing as described above. A shaping tool for shaping the shapedparts 11 and 12 or reform shaping in FIG. 3 abuts against the abuttedsurface 21.

FIGS. 4 and 5 illustrate other examples (tabs 1 (1D and 1E)). Theportions identical to those described above are designated by the samereference characters and their description will not be provided. The tab1 (1D) shown in FIG. 4 includes a shaped part 13 on the display surface20 (or the abutted surface 21) between the pulling-up part 2 and thefixed part 4 and a bead shape part 15 therearound. The shaped part 13 isformed to have a convex shape (upwardly convex shape) on the surfaceside, and the bead shape part 15 is shaped to have a wavy cross-sectionaround the shaped part 13. The tab 1 (1E) shown in FIG. 5 includes ashaped part 14 on the display surface 20 (or the abutted surface 21)between the pulling-up part 2 and the fixed part 4, and a stepped part16 is formed between the shaped part 14 and the fixed part 4 to providea tip up shape part 17 including the shaped part 14, the display part20, and the pulling-up part 2. The shaped part 14 is formed to have aconvex shape (upwardly convex shape) on the surface side, and thestepped part 16 has a step between the shaped part 14 and the fixed part4.

FIG. 6 shows the positions of the display part 20A on the displaysurface 20 of the tab 1. In the example shown in FIG. 6(a), the displaypart 20A is provided within the range of the shaped part 11 provided atthe display surface 20, and in the example shown in FIG. 6(b), thedisplay part 20A is provided in a prescribed range of the displaysurface 20 shaped to be flat. The size L1×L2 of the display part 20A canbe set as appropriate (for example, L1 is from 4.5 mm to 8.8 mm and L2is from 7.0 mm to 11.6 mm).

The can lid to which the tab 1 is attached is produced as shown in FIG.7. In other words, a tab material T unwound from the coil C is firstpassed through a drawing device (for example, a laser marker) 30 and adisplay part drawn for example by laser marking is formed on the surfaceof the tab material T. Then, the tab material T having the display partformed thereon is passed through a tab shaping machine 31 and formedinto the tab 1.

FIGS. 8 and 9 show the process for forming the tab as the tab material Tis passed through the drawing device 30 and the tab shaping machine 31.FIG. 8(a) shows a state in which the display part T1 is drawn on thesurface of the tab material T. The display part T1 is formed in thedrawing device 30 shown in FIG. 7. FIG. 8(b) shows a state in which thetab material T is subjected to hole machining in the tab shaping machine31. Here, the rivet hole 6 and the U-shaped slot 5 are formed in setpositions, and holes T2 and T3 for forming a connected-piece (carrypoint) T4 are formed. In FIG. 9(c), a cut line T5 which defines afurther outer side of the outer peripheral edge of the tab is formed byblanking.

FIG. 9(a) shows a state in which shaped parts are formed inside the cutline T5 and near the rivet hole 6 and the slot 5, and FIG. 9(b) showshow the shaped part 10 is formed outside the slot 5 and the shaped part11 is formed.

As shown in FIG. 10, the shaped part 11 is shaped using a shaping die 40and a shaping tool 41 provided in the tab shaping machine 31. Here, asshown in FIG. 10(a), the display surface 20 having the display part T1of the tab material T formed thereon is provided toward the die hole 40Aof the shaping die 40, so that the shaping tool 41 is provided to opposethe abutted surface 21 of the back surface of the tab material T.

The shaping tool 41 is made to abut against the abutted surface 21 ofthe tab material T, and the shaping tool 41 is pressed into the die hole40A, so that the shaped part 11 is shaped inside the die hole 40A asshown in FIG. 10(b). At the time, shaping is performed while keeping theshaping tool 41 in abutment against the abutted surface 21 on the backsurface side of the display surface 20, and therefore the display partT1 formed on the display surface 20 can be prevented from contacting theshaping tool 41. In this way, the shaped part 11 can be shaped withoutdisturbing the display state of the display part T1 and causing dust orink at the display part T1 to be transferred onto the shaping tool 41.The tab 1 (1C) has the abutted surface 21 formed to be flat, andtherefore the area of the display part T1 can be greater than that ofany of the other tabs 1 (1A and 1B).

The tab material T passed through the tab shaping machine 31 is sent toa conversion press 32 shown in FIG. 7 while the tab 1 is connected tothe tab material T by the connected-piece T4 as shown in FIG. 9(c). Thecan lid body is shaped at the conversion press 32, the rivet hole 6 ofthe tab 1 is positioned with respect to the position of the rivet of thecan lid body, the connected-piece T4 is severed, and the tab 1 isremoved from the tab material T and then the rivet is inserted into therivet hole 6 and crimped, so that the tab 1 is attached to the can lidbody. In this way, the can lid P is obtained.

Table 1 gives a sensory evaluation result about opening operationaccording to the embodiment illustrated in FIG. 1 (in which the displaysurface 20 is on the surface side, the abutted surface 21 is on the backsurface side, and the upwardly convex shaped part 11 is formed).

The sensory evaluation test about opening operation was performed, andin the test, a can lid provided with a tab 1 according to the embodimentwas designated as example 1 (the can lid provided with the tab 1 havingthe display surface 20 on the surface side, the abutted surface 21 onthe back surface side, and the upwardly convex shaped part 11 formed), acan lid identical to example 1 except for the flat shaped part 11 wasdesignated as example 2, and a can lid identical to example 1 except forthe downwardly convex shaped part 11 was designated as example 3.

During opening operation in the sensory evaluation test, the finger isfirst inserted into the gap between the tab 1 and the lid surface whilethe finger tip touches the tab 1, then the finger is guided toward theabutted surface 21 of the tab 1 while, at the same time, the tab 1 islifted by the finger to initially open the can. Then, the inside of thefinger is firmly pressed against the abutted surface 21 of the tab 1 andthe tab 1 is lifted by the inside of the finger, so that the openingpiece defined by the score of the can lid body is pressed down.

In the sensory evaluation test, the tab 1 was lifted up by the inside ofthe finger in each of examples 1 to 3, and awkward feeling experiencedwhen pressing down the opening piece defined by the score of the can lidbody was relatively evaluated. In example 1 with the tab formed with theupwardly convex shaped part 11 or example 2 with the tab formed with theflat shaped part 11, the distance S1 (see FIG. 1) from the surface ofthe pulling-up part on the lower surface side to the abutted surface 21is greater on the upper side (in the Z direction) than that in example 3having the downwardly convex shaped part 11, and therefore it isconsidered that the finger tip is easily moved on the upper side (in theZ direction) when guided to the abutted surface 21 of the tab 1, and theoperational feeling experienced when pulling up the tab 1 improves.

In the sensory evaluation test the evaluation indexes with reference toexample 3 include “⊚” which represents very good operational feeling inpulling up the tab with less awkwardness than example 3, “◯” whichrepresents good operational feeling in pulling up the tab with lessawkwardness than example 3, and “Δ” which represents feeling with alittle more awkwardness than example 3.

As can be clearly understood from Table 1, in example 1 (with theupwardly convex shaped part 11) and example 2 (with the flat shaped part11), generally good operational feeling with less awkwardness resultedthan that in example 3 (with the downward convex shaped part 11). Morespecifically, when the display part T1 is provided on the surface sidein the tab 1 and the upwardly convex shaped part 11 is shaped while theshaping tool is abutted thereupon from the back surface side or when thepart between the pulling-up part and the fixed part is shaped to beflat, the display part T1 with no disturbance as well as goodoperational feeling in opening operation can be obtained. Theconnected-piece T4 is positioned at the pressing-down part, andnecessary rigidity for the tab 1 can be obtained.

Example 1 Example 2 Example 3 Evaluator 1 Δ ◯ — Evaluator 2 ◯ ◯ —Evaluator 3 ◯ ◯ — Evaluator 4 ◯ Δ — Evaluator 5 ◯ ◯ — Evaluator 6 ⊚ Δ —Evaluator 7 ◯ ◯ — Evaluator 8 ◯ ◯ — Evaluator 9 ◯ ◯ —

The embodiments of the present invention have been described in detailwith reference to the drawings, while specific configurations are notlimited by these embodiments and design changes not departing from thegist of the present invention are encompassed by the present invention.These embodiments can divert and combine their features with one anotherif there is no particular inconsistency or problem in relation to thepurposes and structures of the features.

REFERENCE SIGNS LIST

-   1 (1A, 1B, 1C) Tab for opening can lid (tab)-   2 Pulling-up part-   3 Pressing-down part-   4 Fixed part-   5 Slot-   6 Rivet hole-   7 Connected-piece-cutting trace-   8 Curl part-   10, 11, 12, 13, 14 Shaped part-   15 Bead shape part-   16 Stepped part-   17 Tip up shape part-   20 Display surface-   20A Display part-   21 Abutted surface-   30 Drawing device-   31 Tab shaping machine-   32 Conversion press-   T Tab material-   T1 Display part-   T2, T3 Hole-   T4 Connected-piece-   T5 Cut line-   P Can lid

1. A tab for opening a can lid, the tab comprising: a pulling-up partprovided on one end side in a longitudinal direction of the tab; apressing-down part provided on another end side in the longitudinaldirection, a fixed part provided between the pulling-up part and thepressing-down part and formed by being demarcated by a U-shaped slot andfixed to a can lid body; and a curl part formed continuously at aperipheral edge excluding a connected-piece-cutting trace provided atthe pressing-down part, wherein a surface between the fixed part and thepulling-up part is a display surface, and a back surface side of thedisplay surface is an abutted surface against which a shaping tool isabutted.
 2. The tab for opening the can lid according to claim 1,wherein a display part drawn by laser marking or ink jet printing isformed at the display surface, and a shaped part shaped to have a convexshape on the display surface side and to have a concave shape on theabutted surface side is provided between the fixed part and thepulling-up part.
 3. The tab for opening the can lid according to claim1, wherein the abutted surface is shaped to be flat.
 4. A can lidcomprising: the tab for opening the can lid according to claim 1; and acan lid body to which the fixed part is fixed and which has an openingpiece demarcated by a score which is ruptured by pressing down thepressing-down part.